Polypropylene (PP) as a thermoplastic polymer with high breakdown strength as well as high melting point has been considered as a promising candidate for the new generation recyclable cable insulation. However, the tensile yield strength and modulus of elasticity of PP are too large, and the mechanical properties of PP can not meet the requirements of cable materials. In this paper, two kinds of elastomers, i.e. ethylene-octene copolymer (POE) and propylene-based elastomer (PBE), were used to improve the flexibility of polypropylene (PP) so as to make it proper for the main insulation of recyclable power cable. The microstructure of the blends was inspected under electron microscope, and the mechanical properties were tested and compared in this paper. It has been generally accepted that the weak point in a long cable route is cable accessory which connects each cable segment with typical length of several hundred meters. Due to the complex structure of high voltage power cable joints, the electric field is distorted, which is likely to induce interface discharge between the cable insulation and joint insulation. By simulating the electric field distribution of a cable joint, the effect of elastomer content on the interfacial breakdown of PP/SiR was investigated. The test results show that the addition of POE and PBE can greatly prolong the breakdown time of the PP/SiR interface. Discharge initiation time of (PP+POE)/SiR interface is longer than that of (PP+PBE)/SiR, while (PP+POE)/SiR discharge development time is shorter than that of (PP+PBE)/SiR. It is suggested that the decrease of elastic modulus results in the presence of smaller size of air cavities along the interface, which leads to the delay of breakdown time. In addition, the difference of microstructure and trap distribution caused by different compatibilities between the two elastomers and PP is the main factor affecting the interfacial breakdown process.

Young’s modulus of a silicon nanobeam with a rectangular cross-section is studied by molecular dynamics method. Dynamic simulations are performed for doubly clamped silicon nanobeams with lengths ranging from 4.888 to 12.491 nm and cros-sections ranging from 1.22 nm × 1.22 nm to 3.39 nm × 3.39 nm. The results show that Young’s moduli of such small silicon nanobeams are much higher than the value of Young’s modulus for bulk silicon. Moreover, the resonant frequency and Young’s modulus of the Si nanobeam are strongly dependent not only on the size of the nanobeam but also on surface effects. Young’s modulus increases significantly with the decreasing of the thickness of the silicon nanobeam. This result qualitatively agrees with one of the conclusions based on a semicontinuum model, in which the surface relaxation and the surface tension were taken into consideration. The impacts of the surface reconstruction with (2 × 1) dimmers on the resonant frequency and Young’s modulus are studied in this paper too. It is shown that the surface reconstruction makes the silicon nanobeam stiffer than the one without the surface reconstruction, resulting in a higher resonant frequency and a larger Young’s modulus.

The vibration behavior of doubly clamped silicon nanowires with square cross sections is studied by molecular dynamics method. Silicon nanowires have lengths ranging from 4.888 to 12.491 nm and cross sections ranging from 1.22 nm × 1.22 nm to 3.39 nm × 3.39 nm. The size dependence of the resonant frequency is studied in detail. The results show that the vibration behavior of Si nanowire is quite different from the macroscopic beam, and the resonant frequency is much higher than the result based on the continuum theory, but close to the theoretical result based on the semicontinuum approach. Surface reconstruction can strongly affect on vibration behavior. These results demonstrate that the classic theory may not be suitable for analysis of performances of nanostructures, and the conclusion of the study has a certain practical significance on related fields.

Hybrid sterility hinders the exploitation of the heterosis displayed by japonica × indica rice hybrids. The variation in pollen semi-sterility observed among hybrids between the japonica recipient cultivar and each of two sets of chromosome segment substitution lines involving introgression from an indica cultivar was due to a factor on chromosome 5 known to harbor the gene S24. S24 was fine mapped to a 42 kb segment by analyzing a large F2 population bred from the cross S24-NIL × Asominori, while the semi-sterility shown by the F1 hybrid was ascribable to mitotic failure at the early bicellular pollen stage. Interestingly, two other pollen sterility genes (f5-Du and Sb) map to the same region (Li et al. in Chin Sci Bull 51:675–680, 2006; Wang et al. in Theor Appl Genet 112:382–387, 2006), allowing a search for candidate genes in the 6.4 kb overlap between the three genes. By sequencing the overlapped fragment in wild rice, indica cultivars and japonica cultivars, a protein ankyrin-3 encoded by the ORF2 was identified as the molecular base for S24. A cultivar Dular was found to have a hybrid-sterility-neutral allele, S24-n, in which an insertion of 30 bp was confirmed. Thus, it was possible to add one more case of molecular bases for the hybrid sterility. No gamete abortion is caused on heterozygous maternal genotype with an impaired sequence from the hybrid-sterility-neutral genotype. This result will be useful in understanding of wide compatibility in rice breeding.

Microfluidic channel and micro-cavities were fabricated from polyhydroxyalkanoate biodegradable polymer using a direct 20ns, 248 nm excimer laser writing method. First we give a design of the micro-analytical device; second we discussed the laser ablation of biodegradable ppolymer material. The morphology, dimensional accuracy, and surface conditions of the fabricated micro-devices were studied using atomic force microscopy, scanning electron microscopy, optical microscopy, and X-ray photoelectron spectroscopy. Melting of the biodegradable polymer was observed at a fluency of 50mJ/cm2 while ablation was observed at a fluency of 100mJ/cm2.The different width between bottom and top surface are studied in our research. The particle deposited on the polymer surface is seen from the SEM of 248nm laser ablation of PHA. However, the direct burning of PHA can be seen from the optical photo by 355nm laser. Compare to results of PHA with two different lasers, we can see that the 248nm laser is a suitable choice.

In this paper, the band gap and optical properties of hexagonal silicon quantum dots with different diameters are studied based on an ab initio calculations.

A high rate of germination at low temperatures is necessary for economic yields to be maintained. In this paper, the genetic control of low temperature germination ability (LTG) was assessed by the measurement of germination rate (GR), germination rate index (GI) and mean germination time (MGT), and genetically mapped using a set of recombinant inbred lines, derived from a cross between the japonica cultivar 'Asominori' and the indica cultivar 'IR24'. Putative quantitative trait loci (QTL) were validated by testing in two related sets of chromosome segment substitution lines (CSSL). In this genetic background, LTG is under the control of a number of QTL, each of relatively small effect, and is spread over six chromosomes. The most stable of these QTL was for GR, mapping to a segment of chromosome 11 which also carries a QTL for GI. On chromosome 2, qGR-2 not only controlled GR, but also was associated with GI and MGT. Significant differences in LTG were detected between 'Asominori' and some CSSL harbouring qGR-2 or qGR-11.

Molecular dynamics simulations are carried out to characterize the mechanical properties of [001] and [110] oriented silicon nanowires, with the thickness ranging from 1.05nm to 3.24 nm. The nanowires are taken to have ideal surfaces and (2×1) reconstructed surfaces, respectively. A series of simulations for square cross-section Si nanowires have been performed and Young’s modulus is calculated from energy–strain relationship. The results show that the elasticity of Si nanowires is strongly depended on size and surface reconstruction. Furthermore, the physical origin of above results is analyzed, consistent with the bond loss and saturation concept. The results obtained from the molecular dynamics simulations are in good agreement with the values of first-principles. The molecular dynamics simulations combine the accuracy and efficiency.

The objectives of this study were to evaluate effects of feeding propylene glycol (PG) on feed intake, milk yield and milk composition, blood metabolites and energy balance in Holstein dairy cows from 1 to 63 days in milk. Thirty-two multiparous cows, blocked by lactation number, previous 305-day milk production and expected calving date, were arranged into four groups in a randomized block design. Treatments were: control, low PG, medium PG and high PG with 0, 150, 300 and 450 ml PG per cow per day, respectively. The supplement of food grade PG (0.998 g/g PG) was hand-mixed into the top one-third of the daily ration. Cows were fed ad libitum a total mixed ration consisting of forage and concentrate (50 : 50, dry matter basis). Feed intake, milk yield and milk components were not affected (P > 0.05) by PG supplementation. Overall, body weight (BW) loss tended (P < 0.08) to be linearly reduced, and energy status was linearly improved with increasing PG supplementation. Concentrations of glucose in plasma were higher for cows fed PG relative to control (55.6 v. 58.9 mg/dl) and linearly increased (P < 0.01) with increasing PG supplementation. Plasma concentrations of non-esterified fatty acids and beta-hydroxybutyrate were linearly increased, but urine acetoacetate concentration was quadratically changed with the highest for control diet and the lowest for 450 ml/day of PG. These results indicated that supplementation of PG in the early lactating cow diets had minimal effects on feed intake and milk production, but may potentially reduce contents of milk fat and milk protein. Supplementation of early lactating dairy cow diets with PG is beneficial in terms of improving energy status and reducing BW loss.

Neuropathology and Applied NeurobiologyVolume 34, Issue 3 p. 373-374 Neuropathology in China W. W. Zhang, W. W. Zhang Department of Neurology, Beijing Military General Hospital,Search for more papers by this authorD.-H. Lu, D.-H. Lu Department of Pathology, Beijing Xuan-wu Hospital, Beijing, ChinaSearch for more papers by this author W. W. Zhang, W. W. Zhang Department of Neurology, Beijing Military General Hospital,Search for more papers by this authorD.-H. Lu, D.-H. Lu Department of Pathology, Beijing Xuan-wu Hospital, Beijing, ChinaSearch for more papers by this author First published: 15 February 2008 https://doi.org/10.1111/j.1365-2990.2008.00939.xCitations: 2Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume34, Issue3June 2008Pages 373-374 RelatedInformation

ABSTRACT Fat content (FC) and fat index (FI) play an important role in determining quality of eating and nutrition for rice. The objective of this study was to determine genetic information during the grain‐filling period. Seventy‐one recombinant inbred lines (RILs) derived from a cross between japonica cultivar Asominori and indica cultivar IR24 were used to analyze the developmental behavior of FC and FI by conditional and unconditional quantitative trait loci (QTL) mapping methods. At four developmental stages of grain filling, 11 unconditional QTL and 10 conditional QTL for FC as well as 11 unconditional QTL and eight conditional QTL for FI were identified. In unconditional QTL analysis, qFC‐11‐2 and qFI‐3 were consistently detected at 21 and 28 days after flowering (DAF), whereas all the conditional QTL for FC and FI could be detected at only one stage. Nine conditional and nine unconditional QTL for FC and FI were detected in the earlier three stages while three and two unconditional QTL for FC and FI, respectively, were detected in the mature stage, which suggested that more QTL could be found in the early developmental stages. The qFC‐1‐2 and qFI‐1‐2, qFC‐2‐2 and qFI‐2, qFC‐4 and qFI‐4 , and qFC‐9 and qFI‐9 were located on the vicinal marker intervals. The present study suggested that accumulation of fat was governed by time‐dependent gene expression. In addition, dynamic QTL mapping might be a valid way to reveal more genetic information about the fat accumulation.

The karyotype of the spiny eel (Mastacembelus aculeatus) has highly evolved heteromorphic sex chromosomes. X and Y chromosomes differ from each other in the distribution of heterochromatin blocks. To characterize the repetitive sequences in these heterochromatic regions, we microdissected the X chromosome, constructed an X chromosome library, amplified the genomic DNA using PCR and isolated a repetitive sequence DNA family by screening the library. All family members were clusters of two simple repetitive monomers, MaSRS1 and MaSRS2. We detected a conserved 5S rDNA gene sequence within monomer MaSRS2; thus, tandem-arranged MaSRS1s and MaSRS2s may co-compose 5S rDNA multigenes and NTSs in M. aculeatus. FISH analysis revealed that MaSRS1 and MaSRS2were the main components of the heterochromatic regions of the X and Y chromosomes. This finding contributes additional data about differentiation of heteromorphic sex chromosomes in lower vertebrates.

The elongation of the cooked grain determines the cooking and eating quality of Basmati rice. The identification of stable quantitative trait loci (QTLs), especially those from non-Basmati types, will extend the genetic basis of the Basmati type and facilitate the breeding of high-quality varieties. A set of recombinant inbred lines derived from an indica x japonica hybrid was used to identify QTLs controlling the elongation ratio (ER), elongation index (EI), and water absorption (WA) of the cooked grain. Three ER QTLs on chromosomes 2, 4, and 12, two EI QTLs on chromosomes 2 and 5, and two WA QTLs on chromosomes 2 and 6 were detected. Four of these QTLs were validated using a set of established chromosome segment substitution lines. The genetic effect of qER-2 was explored in an analysis of segregating generations, using 8 newly developed simple sequence repeat markers. Two tightly linked loci (qER-2a and qER-2b) were identified on chromosome 2.

Partial abortion of female gametes and the resulting semi-sterility of indica x japonica inter-subspecific rice hybrids have been ascribed to an allelic interaction, which can be avoided by the use of wide compatibility varieties. To further understand the genetic mechanism of hybrid sterility, we have constructed two sets of hybrids, using as male parent either the typical japonica variety Asominori, or the wide compatibility variety 02428; and as female, a set of 66 chromosome segment substitution lines in which various chromosomal segments from the indica variety IR24 have been introduced into a common genetic background of Asominori. Spikelet semi-sterility was observed in hybrid between CSSL34 and Asominori, which is known to carry the sterility gene S31 (Zhao et al. in Euphytica 151:331-337, 2006). Cytological analysis revealed that the semi-sterility of the CSSL34 x Asominori hybrid was caused primarily by partial abortion of the embryo sac at the stage of the mitosis of the functional megaspore. A population of 1,630 progeny of the three-way cross (CSSL34 x 02428) x Asominori was developed to map S31. Based on the physical location of linked molecular markers, S31 was thereby delimited to a 54-kb region on rice chromsome 5. This fragment contains eight predicted open reading frames, four of which encode known proteins and four putative proteins. These results are relevant to the map-based cloning of S31, and the development of marker-assisted transfer of non-sterility allele inducing alleles to breeding germplasm, to allow for a more efficient exploitation of heterosis in hybrid rice.

II-32A, an elite male-sterile line of rice (Oryza sativa L.), has been widely used for the production of hybrid rice seed in China. Heading date in most combinations using II-32A shows transgressive inheritance or similarity to the latter parent, but the genotype of II-32A with respect to major genes for heading time is unknown. This limits the further exploitation of this sterile line in breeding and hybrid seed production. Using a number of major gene heading date isogenic lines and heading date QTL near-isogenic lines, we genetically analyzed II-32B under both long- and short-day conditions. We show that II-32B carries two photoperiod-sensitive genes, E1 and E3, a recessive late-heading gene, ef-1, and a photoperiod-sensitive allele, Se-1(u). In addition we identified in II-32B a recessive inhibitor for E1 or Se-1(n) and other modified photoperiod-sensitive genes. The heading-date constitution of II-32A was determined to be E(1)e(2)E(3)Se-1(u)ef-1i-Se-1.